Secondary time-keeping apparatus



Jan. 6, 1953 A. a. BENSON SECONDARY TIME-KEEPING APPARATUS 5 Sheets-Sheet 1 Filed July 9, 1948 INVENTOR ALFRED B. BENSON AGENT Jan. 6, 1953 A. B. BENSON 2,624,170

SECONDARY TIME-KEEP ING APPARATUS Filed July 9, 1948 5 Sheets-Sheet 5 INVENTOR ALFRED 8. BENSON AGENT Patented Jan. 6, 1953 UNITED STATES PATENT OFFICE SECONDARY TIME-KEEPING APPARATUS Alfred B. Benson, Endicott, N. Y., assignor to International Business Machines Corporation, New York N. Y., a-corporation of New York Applicationluly 9, 1948, Serial No. 37,841

a copending-applicati'on of R. B. Johnson and E: F. Geiger, Serial'No. 664,933; filed' April 25, 1946; for Secondary Time-Keeping Apparatus.

Inthe copending application above referred to the clock mechanism is adapted to be uniformly and continuously drivenby means of'a' synchronous alternating current motor which receives its impulses from the commercial Gil-cycle power line. Means. are also provided" whereby an electrical signal is transmittedfto the secondary clock over the. regular power line at a moment which occursslightly before the fifty-ninth minute of each standard time hour and which terminates precis'ely at the fifty-ninth minute of the hour, such an impulse servingto initiate a correction cycle whereby, if'the secondary clockis running slow with respect to standard time at. the fifty ninth minute of the hour, it will be brought up to the correct time. during the sixtieth minutev of the hour so. that when the sixtieth minute is completed and the first minute of the next succeeding. hour commences, the. clock will be accurately synchronized with thestandard time source.

Thespecial or time correcting signal whichis imparted to-thesecondary clock over the reguin commercial channel is preferably of a high frequency nature. and it is employed to. energize a magnet.which,.by tripping a latch, initiates the correction cycle.

Briefly, in the abovementioned copending application of R. B. Johnson et al., the clock mechanism includes a. seconds shaft, a minutes sleeve and. an h ourssleeve, all. of which are concentrically mounted for movement at their respective rates of rotation about a common axis. The drive existing from the synchronous motor to the minutes sleeve which carries the minutehand includes a friction slip device by means of which the-minutes sleeve is normally driven at its usual rate ofrotation, i. e., one revolution per hour. However, during the. correction cycle if the minute hand happens to be slow at the commence ment'of the cycle a clutch device is set into operation and this device picks up the minutes sleeve "and" rotates the same at acomparatively" 2. fast rate of rotation. The correction device'includes a one revolution clutch mechanism which operates to clutch the minutes sleeve to the seconds shaft in operative driving relationship. As disclosed in the above mentioned application, the correction mechanism, including the clutch device, is mounted for operation about the samecommon axis as that of the seconds shaft and minutes and hours sleeves. The present invention is designed as an improvement over'the' structure shown in the above mentioned applica tion in that the correction mechanism, includ ing the one revolution clutch device, has been removed from the common axis of therotatable time indicating elements and placed on a separate counter shaft, thereby materially relieving congestion around the axis of the clock hands; This feature constitutes one of the principal objects of the invention.

In the above mentioned copending application, means are provided during thecorrection cycle for interrupting rotation of the'seconds shaft and, consequently, of the seconds hand' when the latter arrives at the sixtieth secondposition and for holding the hand and shaft thus interrupted until the correction cycle'is'completed, after which the seconds shaft and hand are released precisely on time that they may resume rotation in coincidence with standard" time at the commencement of an even hour. The present invention has, as an additional'object, the provision of a simplified arrangement of parts for accomplishing the above mentioned.

feature and wherein the element which is' employed for engaging the one-way, one revolution clutch during the correction cycle is also employed for blocking or otherwise interrupting'the movement of the seconds shaft until such time" as the correction cycle has'been completed.

Other objects of the invention will be ointed out in the following description and claim and illustrated in theaccompanying drawings, which disclose, byway of example, .the principle of the invention and the'best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. l is a front elevational view of asecondary clock mechanism constructed in accordance-with the principles of the present invention. In this View; the dial face clock hands, clockcasin'g and other parts have been removed to moreclearly reveal the nature of the invention.

Fig. 2 is an enlarged sectional view taken substantiaily alon the line 2'-2 of Fig. 1'.

Figs. 3 and 4 are fragmentary'views of the clock mechanism of Fig. 1 showing the correcting mechanism and in various selected positions to illustrate the operation thereof.

Fig. 5 is a sectional View taken substantially along the line 55 of Fig. 2.

In all of the above described views, like characters of reference are employed to designate like parts throughout.

Referring now in detail to the drawings wherein a preferred form of an automatically regulated secondary clock construction is shown, the clock comprises the usual face plate or dial face I0, seconds hand I 2, minutes hand I 4 and hours hand IE3. The parallel front and rear support plates are indicated at I8 and 20 respectively and they are suitably secured in their predetermined spaced relationship by pillars 22. An electric driving motor MI is suitably supported, as for example, by means of screws 25, on the rear plate 20 and is preferably of the self-starting synchronous type which is adapted to be driven at a predetermined time rate from the available frequency regulated commercial alternatin current power line. v

The output shaft 26 of the motor M has mounted thereon a relatively wide splined pinion 28 which, when the motor is assembled on the rear plate 20, fits into and meshes with an internally threaded cup-shaped member 30 rotatably mounted on a seconds shaft 32, the latter being rotatably supported in the sleeves 64 and 05 mounted in the front plate I8.

A spider-like spring friction member 35 bears against one side of the cup-shaped member 30 and is formed with a series of spring fingers 35 which bear at their ends against one side of a disc 38 mounted on and secured to the shaft 32. The member 34 thus operates in the manner of a friction member for imparting movement from the cup-shaped member 30 to the shaft 32 and the latter is constrained to follow the rotational movements of the member 30 during normal timekeeping operations. The friction member 34 permits relative movement between the seconds shaft 32 and the pinion 28 when such relative movement is required for time-correcting operations, as will be subsequently described.

The disc 38 has formed thereon an outwardly extending stop finger S6. The seconds hand I2 is mounted upon the outer end of the seconds shaft 32. Thus the stop arm 06 and seconds hand I2move together with the seconds shaft 32, and the stop finger Q6 thus occupies a definite angular position with respect to the seconds hand I2 for any given time-indicating position of the latter..

Agear 42 carried by and fixed to the seconds shaft 32 and which may be considered as the seconds gear of the clock mechanism is in mesh with a large gear 48 (Figs. 1 and 2) mounted on a shaft 50 extending between the front and rear plates I8, 20 of the clock works mechanism. The shaft 50 carries a small gear 52 which meshes with a large gear 54 loosely disposed on the seconds shaft 32. A minutes sleeve 64 surrounds the seconds shaft 32 and has formed thereon a minutes gear 62. A spider-like friction member 60 is interposed between the gear 54 and the gear 62 and permits relative motion between the constantly rotating gear 55 and the gear 62 when necessary during the time-correction cycle or period, as will appear presently.

An hours sleeve 66 is rotatably mounted on the minutes sleeve 64 and is driven at the proper time rate of one revolutionevery twelve hours by gearing including a large gear 68 which meshes with the minutes gear 62 and a small gear 10 which meshes with the relatively large hours driving gear 72 carried on the hours sleeve 66. The gears 58 and I0 are carried on a common stub shaft 14 secured in the front plate I8. The hours hand I6 is mounted on the forward end of the hours sleeve 66 which terminates short of the minutes sleeve 60.

Referring now to Figs. 1 and 2, the pinion 28 which is carried by the motor shaft 26, in addition to driving the cup-shaped gear 30, as previously described meshes with and drives a relatively large gear journaled on the rear plate 20. The gear 80 in turn meshes with a small gear 82 fixedly mounted on a countershaft 84 extending across the clock works and rotatably journaled in the front and rear plates I8 and 20 respectively. The gear 82 is formed with a disc portion 86 thereon having a series of relatively small peripheral teeth 88 thereon. The teeth88 are relatively small and closely spaced and these teeth are designed for clutching engagement with a rela tively small pawl-like clutch piece 94 which is pivoted as at 95 to one side of a relatively large time-correcting disc 90 which is loosely mounted on the constantly rotating counter shaft 84 immediately to one side of the toothed disc 86. The clutch piece 94 is spring pressed as at 98 in a counter-clockwise direction, as viewed in Figs. 3 and 4, and is provided with a clutch tooth I08 which bears against the periphery of the toothed disc 85, thereby permitting engagement between the two discs 80 and 90 so that the latter is clutched to follow the movements of the former.

The periphery of the disc 90 has formed therein a slot H0 across which one end II2 of the clutch piece 95 extends. A lever I I6 is mounted on a rock shaft IIB extending across the frame pieces I8, 20, and is provided with a laterally turned end I20. A coil spring I22 is anchored at one end thereof to an extension I24 of an armature I25 associated with an electromagnet M, the armature being mounted on the rock shaft H0. The other end of the coil spring I22 is anchored to a bracket I 26 which is secured as at I 28 to the magnet support !30, this latter support being secured as at I32 to the frame piece 20.

From the above description of parts it will be seen that the spring I22 by exerting a pulling effect on the extension I20 of the armature I25 normally causes the armature to be moved in a. clockwise direction, as viewed in Fig. 3, thus moving the rock shaft H0 in such a direction as to cause the laterally turned end I20 of the arm II6 to enter the slot H0 and by a camming action urge the clutch piece 94 in a clockwise direction to withdraw the tooth I08 thereon from engagement with the toothed periphery of the disc 86. The laterally turned end I20 of the arm I I 6 when in the slot H0 also serves to hold the disc 90 stationary in a fixed angular position. Upon energization of the electromagnet M, its armature I25 will be swung in a counter-clockwise direction, thus moving the rock shaft H8 in a. counterclockwise direction and causing the laterally turned end I20 of the arm II6 to be withdrawn from the slot IIB, thereby permitting the clutch piece 94 to be moved under the influence of the spring as in a counter-clockwise direction so that the tooth I08 engages the toothed periphery of the disc and effectively couples the two discs and 05 so that they will rotate in unison. Once the laterally turned end I20 of the arm IIB has left the slot II 0, the coupling between the two par.ts.86. and 90 iscomplete and-thelatter disc commences; to. rotate. Upon deenergization of the; electromagnet Mthe laterally turned end I20 thereof: willbear against the smooth periphery of the disc. 60 and slide thereon until such a time as the latter discv has executed one complete revolution,. at which time theslot I I will again come into register with the laterally turned end I of th arm II6. sov that the end I20 may again enter the slot and disengage the driving connection between the continuously rotating disc 06 and the disc 90. The clutch piece 94 and disc 86, therefore, in efiect constitute a one-revolution clutch which becomes eiTeotive upon initial energization of the magnet M to couple the parts together and which becomes effective at the end of one complete revolution of thedisc 90 touncouple the two parts.

Referring now to. Figs. 2 and 4, the countershaft 04 has loosely disposed thereon a gear I46 which meshes with the gear 68 and which in turn meshes with the minutes gear 62. The gear ratio between the gears I40, 68 and 62 is such that the gear I4 is adapted to rotate once every hour. In other words, the gear I is operatively connected to the minutes sleeve 64 by a 1:1 gear ratio and the particular orientation of the gear I40 at any instant is always dependent upon the orientation of the minutes sleeve 64. During normal timekeeping movements of the minutes sleeve 64, the gear I40 moves according to chronological time and follows the movements of the minutes sleeve 64. During the time-correcting cycle if the minute hand I4 is slow with respect to chronological time, the gear I40 is caused to drive the minutes gear 62 at a comparatively rapid rate of rotation to in turn drive the minutes sleeve 64 and bring the minutes hand I4 up to proper chronological time at the end of the time-correcting cycle. Toward this end, the gear I40 has integrally formed therewith a time-correcting disc I42 on which there is formed a radially projecting finger I44. A pivoted dog I46 is mounted on one side of the time-correcting disc and is spring biased in a counter-clockwise direction, as viewed in Fig. 4. A limit stop in the form of a pin I48 formed on the disc 90 serves to limit the extent of inward movement of the dog I46 relative to the center of the disc 9. The dog I46 has a portion I66 thereof extending across the peripheral slot I I6 and this portion I60 of the dog I46 is designed for camming engagement with the laterally turned end I26 of the arm II6 so that when this end I26 is disposed within the slot IIO, the dog I46 is maintained in a retracted position. When the laterally turned end I20 is withdrawn from the slot H6 upon energization of the magnet M in the manner previously described, the dog I46 is permitted to move to its normal position wherein the extreme end I62 thereof is projected into the path of movement of the finger I44 formed on the disc I42. During the time-correcting cycle when the disc 90 has been released by the laterally turned end I20 of the arm II6 with the clutch piece 64 effecting clutching engagement between the two discs 90 and 86, the end of the dog I46 will overtake the relatively slowly moving finger I44 of the disc I42 and engage the same and thereafter forcibly carry the disc I42 in a clockwise direction, as viewed in Fig. 5, thus turning the gear I40 to in turn drive the gears 63 and 62 and, consequently, turning the minutes sleeve 64 at the rate of one revolution per minute to bring the minutes hand I4 up to chronological or standard time at the end of the correction cycle. The correctionv cycle is terminated by movement of the laterally turned end I20 of the lever II6 into the peripheral slot H0 in the cam 60, thus moving the dog I46 to its retracted position and releasing the finger I44 which then resumes its normal movements at the rateof one revolution per hour.

Referring now to Figs. 1, 2 and 3, the diameter of the disc 36 and the extent of the stop finger 46 which moves in unison with the seconds hand I2 is such that when the laterally turned end I20 of the arm H6 is withdrawn from the slot H0 and rests against the periphery of the disc 90.

this laterally turned end is directly in the path of movement of the stop finger 46. Conversely, when the laterally turned end I2 is disposed within the slot H0, this end clears the finger 46 and presents no obstruction to normal rotation of the disc 38 and, consequently, of the seconds hand I2 at its normal rate of rotation of one revolution per minute. Immediately upon commencement of the correction cycle after the magnet M has become energized, the laterally turned end I20 of the arm IIB will be projected into the path of movement of the seconds hand I2 which, depending upon the particular position of the seconds hand at the time the correction cycle commences, will ultimately come to rest against one side of the laterally turned end I20 of the arm I I6 and arrest further movement of the disc 38 and, consequently, of the seconds hand I2 until such time as the correction cycle has been completed and the laterally turned end I20 again enters the slot I ID in the disc 90.

From the above description of parts it will be seen that the arm I I6 performs a fourfold function. Firstly, by its position within the slot IIO, it serves to obstruct movement of the disc and hold the latter stationary at all times, except during the correction cycle. Secondly, when this laterally turned end I20 is withdrawn from the slot H0 at the commencement of the correction cycle, it releases the clutch piece 94 for engagement with the periphery of the toothed disc 86, thereby connecting the discs 86 and 60 for movement in unison during the correction cycle. Thirdly, the laterally turned end I20 serves to move the pivoted dog I46 into and out of the path of movement of the finger I44 to thus efiect driving engagement between the disc 90 and the disc I42 to impart the relatively rapid rate of rotation of the former to the latter to bring the minutes hand rapidly up to chronological or standard time during the correction cycle. Fourthly, the laterally turned end I20 of the arm II'6 serves to block movement of the finger 46 during the correction cycle to arrest movement of the seconds hand at the zero position of the clock dial and to hold the seconds hand thus arrested until the correction cycle has been completed, after which time the seconds hand is released and permitted to proceed around the face of the clock dial in the normal manner in exact coincidence with chronological or standard time.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the apparatus illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to

7 be limited only as indicated by the scope of the following claim.

What is claimed is:

In a time-keeping apparatus, a driving motor adapted to operate continuously at a uniform time rate, a time member mounted for rotation about an axis, a driving connection including a friction slip device between said motor and time member for driving the latter at its normal timekeeping rate, and a second driving connection between said motor and time member for driving the latter at a rate faster than its normal time-keeping rate, said latter driving connection comprising a pair of clock-advancing members mounted for rotation about a common axis removed from the axis of rotation of said time member, means operatively connecting one of said clock-advancing members to the time member for rotation thereof chronologically in unison, normally disconnected one-revolution clutch means operatively connecting the other clockadvancing member and motor in driving relationship, a one-way lost-motion coupling between said clock-advancing members for driving of the time member from the motor through said clock-advancing members, and signal-responsive means for periodically rendering said clutch means operative.

ALFRED B. BENSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,274,221 Stone Feb. 24, 1942 2,332,278 Stone Oct. 19, 1943 2,569,815 Larrabee Oct. 2, 1951 

